Outsole structure for a shoe, method for assembling outsole to an upper, and shoe obtained by said method

ABSTRACT

A shoe outsole comprising a substantially flat body with a top face and a lower face exhibiting a distribution of tread protrusions. The protrusions include at least one peripheral protrusion extending beyond the peripheral edge and defining a top abutment surface displaced generally downward relative to the top face of the body. In a method of assembling the outsole to a shoe upper, for each peripheral protrusion, a cut is formed in the upper, developing in accordance with the profile of the area of superimposition between the peripheral protrusion and the body&#39;s lower face. The method provides for insertion of the at least one peripheral protrusion into the appropriate cut so as to enable passage of the protrusion below the upper as a superimposition reversal between the upper and the body.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of footwear and to therelevant manufacturing processes. In particular, it relates to a newoutsole structure of natural or synthetic rubber and to the method ofassembling it to the upper during the shoe manufacturing process. Theinvention relates also to the shoe obtained in this way.

BACKGROUND OF THE INVENTION

Various types of shoes are known wherein the upper, usually made ofleather, has a base intended to be combined with a natural or syntheticrubber bottom or outsole, to obtain the shoe sole. In particular, therubber outsole exhibits a number of outwards protrusions which,inserting into openings formed to this end in the base of the upper,become exposed, thus forming the actual sole tread. In practice, theoutsole body is superimposed to the base, being kept on the inside ofthe shoe. The base, in the area without protrusions, remains exposed andvisible between the protrusions, thus attaining an appreciated aestheticresult, more valuable than that of an outward facing surface completelymade of rubber.

Besides the lower face of the outsole, the protrusions may also beformed along the perimeter, so as to improve the sole resistance andanti-slip properties and, in certain cases, also to obtain a pleasantaesthetic effect. However, in this case, an external reinforcing seamconnecting the outsole to the upper must necessarily be distributed onthe upper leather, which is unavoidably superimposed externally to therubber, close to the relevant protrusions. This causes a loss in thevery aesthetic value of the product, which is made even more serious bythe leather sharp cut edge, which remains visible on the outside. Thehandmade assembly between outsole and upper, moreover, can be difficultdue to the need of maintaining an accurate superimposition of theleather during the stitching.

Due to these disadvantages, sometimes the external protrusions areobtained with separate rubber portions applied subsequently, which ofcourse considerably increases manufacturing times and costs. Thesuperimposition may also be avoided, using an internal support element(a so-called “midsole”); similarly, this is a manufacturing difficultywhich moreover decreases the comfort of the shoe.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the disadvantagesmentioned above by providing a new outsole structure and a new method ofassembling the same to the upper which should allow obtaining shoes withside protrusions along the perimeter of the sole, substantially of thetype mentioned above, with a considerably improved aesthetic result,with elementary and low cost manufacturing methods, further improvingthe comfort of the shoe and the durability requirements thereof.

Such object is achieved by the rubber outsole for a shoe whose essentialfeatures are defined by the first of the annexed claims. A methodaccording to the invention for the assembly between the outsole and anupper is essentially characterised by what specified in the annexedclaim 4.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the outsole structure for a shoe, of themethod of assembling the outsole to an upper, and of the shoe thusobtained according to the present invention will appear more clearlyfrom the following description of an embodiment thereof, made by way ofa non-limiting example, with reference to the annexed drawings, wherein:

FIG. 1 shows a schematic view of a cross section of a shoe obtainedaccording to the invention;

FIG. 2 shows a partial axonometric view of the lower side of a rubberoutsole according to the invention, shown separately, that is to saybefore the assembly to the upper;

FIG. 3 shows again the outsole of FIG. 2, in a top axonometric view;

FIG. 4 shows a partial view of an upper, developed on a plane, intendedfor the assembly with the outsole portion of FIGS. 2 and 3; and

FIG. 5 shows a schematic side view of a variant of a shoe obtainedaccording to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1 to 4, an outsole for a shoe according to theinvention comprises a body 1 with substantially flat development, madeof natural or synthetic rubber, shaped in accordance with the outline ofthe entire shoe sole or of just a portion thereof (for example the tip).In this second case, the shoe sole will be provided with two (or more)outsole semi-components physically separate from one another.

Body 1 therefore exhibits a top face 2, smooth in the schematicrepresentation of FIG. 2 but which could actually be grooved or cut invarious ways, intended for the foot's support with the interposition ofan inter-sole and/or insole. Body 1 further exhibits a lower face 3 fromwhich a distribution of protrusions projects, adapted for defining theactual sole tread. Among these protrusion, protrusions 4 can be noticedarranged in the inner zone of the lower face 3, that is, in asubstantially central position, and peripheral protrusions 5, arrangedalong the face peripheral edge. In particular, among the peripheralprotrusions 5, which shall be discussed in detail hereinafter, a tipprotrusion 5 a and two side protrusions 5 b can be seen.

A leather upper 6, shown in cross section in the assembled configuration(that is, of the finished or semi-finished shoe as shown in FIG. 1)develops with a base 6 a defined between side vertical walls 6 b. Theupper 6 is intended for being assembled with the outsole, to completethe manufacture of the sole and, at the same time, integrate it in theshoe. To this end, as shown in FIG. 4, in the area intended for formingthe base 6 a, windows 7 are formed in upper 6. The windows 7 have aprofile that matches the profile of the central tread protrusions 4,which are intended for engagement with the same openings 7.

On the upper 6, in the area of transition between base 6 a and sidewalls 6 b, there are provided cuts 8, 9, formed in correspondence withrespective peripheral protrusions 5 b, 5 a. More precisely, cuts 8, 9extend so as to be in accordance with the profile of the area ofsuperimposition between the respective peripheral protrusions 5 b, 5 a,and the lower face 3, an area which, more generally speaking, is inpractice defined between the inner edge of the protrusions and theperipheral edge of body 1 (shown in dotted lines in FIG. 2).

In fact, with reference again to the peripheral protrusions, and withparticular reference to FIGS. 1 and 3, there can be noted that each ofthem extends beyond the peripheral edge of body 1, projecting then alsoupwards and defining respective top abutment surfaces 10 a, 10 b. Thelatter, along the junction with body 1, are displaced downwardlyrelative to top face 2. The extent of such displacement is preferablyequal to, or slightly greater than, the thickness of the leather of theupper 6. Still according to a preferred solution, the abutment surfaces10 a, 10 b develop according to the imaginary continuation of the lowerface 3 beyond the peripheral edge of body 1.

The outsole and the upper are assembled as follows. After havingsuitably distributed the suitable adhesive substances on the relevantsurfaces, the outsole is superimposed to the upper 6, inserting aperipheral protrusion 5 a in the relevant cut 8. The central protrusions4 penetrate windows 7 of base 6 a of the upper. The lower face 3 of body2, in the area which is free from protrusions, will abut on base 6 a,thus being coated thereby. The other peripheral protrusions 5 a, 5 b arefinally introduced in the respective cuts 8, 9. The deformability ofboth the leather and the rubber of which the upper and the protrusionare respectively formed, assist in allowing such operation.

In this way, peripheral protrusions 5 a, 5 b pass below upper 6 (theterm below being referred to the shoe usage position) through the cuts8, 9, as clearly shown in FIG. 1. This figure shows how in the practice,due to the particular configuration and position of the peripheralprotrusions relative to body 1, the leather of upper 6 and body 1 itselfcarry out a superimposition reversal, highlighted at reference index S,with the leather passing from the outside the body (in the area of base6 a) to the inside of the peripheral protrusions 5 a, 5 b, abuttingagainst the relevant top surfaces 10 a, 10 b.

If, as mentioned, the displacement of the top surfaces 10 a, 10 b isequal to about the thickness of the leather, the shift from the outsoleto the side walls 6 b of the upper will cause no discontinuity, andtherefore, no inconveniences to the wearing comfort of the shoe. If theabutment surfaces 10 a, 10 b substantially begin as an imaginarycontinuation of the lower face 3, there will be obtained the furtheradvantageous result of minimizing the deformation required to the upperfor realising the engagement. Accordingly, the forming of wrinkling,chipping or inaccuracies in general will be avoided.

With reference now to FIG. 5, the invention, according to methodssimilar to those described above, may be applied also in the case of anupper 16 which, on the top side, exhibits a continuous development fromthe outset. In practice, the side walls 6 b are integrally connectedabove the foot before the assembly to the outsole, unlike the previouscase where the connection occurred thanks to a closing operationfollowing said assembly. In this case, it is the base 6 a which isinitially discontinuous—that is, longitudinally divided into twohalves—and the procedure to be followed for carrying out the assemblywill be therefore slightly different; the two base halves will be thelast to be arranged between the protrusions, after the superimpositionreversal between the outsole and the upper has already been carried out.

It will then be appreciated that, according to the invention, when atthe end of the gluing step the external fastening stitching between theoutsole and the upper must be carried out, the same stitching can beapplied right over the peripheral protrusions, which in this case areexternally superimposed to the upper. The aesthetic result is thereforeconsiderably improved as compared to the conventional solution withstitching running over the upper. The leather cut edges remain fullycovered by the relevant protrusions, and therefore invisible. Thehandmade assembly between the outsole and the upper is very easy, sinceit is the same and very reversal engagement between the outsole and theupper, along with the particular configuration of the peripheralprotrusions, that keeps the superimposition steady and accurate. Noadditional operations of separate rubber portions to be appliedsubsequently, nor the use of an internal “midsole” are required, so themethod is quick and inexpensive and the shoe comfort qualities are notworsened.

The method, even though with a less satisfactory result, can be carriedout also with an outsole wherein the peripheral protrusions have no topabutment surfaces displaced downwards, since the cuts formed in theupper, possibly with the aid of simple reference signs on the outsolerubber, is sufficient to carry out the superimposition reversalmentioned above. The reversal will clearly exhibit variable dimensionalfeatures according to the materials used.

Obviously, the protrusions, both the peripheral ones 5 a, 5 b and thecentral ones 4, can vary in number, shape and arrangement. Accordingly,windows 7 and cuts 8, 9 on the upper will be adapted, as it can beappreciated by a simple comparison between FIG. 1 and FIGS. 2 to 4,wherein different distributions of central protrusions 4 are noticeable.Then, as confirmed by the variant proposed in FIG. 5, it can be seenthat the peripheral protrusions can even extend also towards the outsolecenter, and that therefore actual independent central protrusions maynot be present. In this case, the cuts formed in the upper 16 are muchmore extended as compared to the previous solution, and they becomeactually window-shaped.

Even though in the present description reference was made to leather andrubber as materials used respectively for the upper and the outsole, itis clear that the invention may be applied also with differentmaterials, whenever there raises a problem similar to that described inthe introduction. In particular, the rubber outsole could also includehide inserts or portions.

Other variants and/or changes may be brought to the outsole structurefor a shoe, to the method of assembling the outsole to an upper, and tothe shoe thus obtained, according to the present invention without thusdeparting from the scope of protection of the invention itself.

1. A shoe outsole made of a natural or synthetic rubber material, theoutsole comprising a substantially flat body with a top face and a lowerface, and having a selected distribution of tread protrusions comprisingat least one peripheral protrusion projecting from the peripheral edgeof the body, the at least one peripheral protrusion extending beyond theperipheral edge defining a top abutment surface displaced generallydownward relative to a top face of the body.
 2. The outsole set forth inclaim 1, wherein the extent of the displacement between the abutmentsurface and the top face is equal to or slightly greater than thethickness of the material with which the upper is made.
 3. The outsoleset forth in claim 1, wherein the abutment surface substantiallydevelops starting from an imaginary continuation of the lower face ofthe body beyond the peripheral edge.
 4. A method of assembling a shoeoutsole to a shoe upper, the outsole comprising a substantially flatbody with a top face and a lower face, and having a selecteddistribution of tread protrusions comprising at least one peripheralprotrusion projecting from the peripheral edge of the body, the methodcomprising the steps of: (i) arranging the outsole in superimpositionwith the upper wherein, for each protrusion, a cut is formed in theupper, the cut developing generally in accordance with the profile ofthe area of superimposition between the peripheral protrusion and thebody's lower face with the profile of the area delimited between theinner edge of the protrusion and the peripheral edge of the body; andinserting the at least one peripheral protrusion in an appropriate cutso as to enable passage of the protrusion below the upper as asuperimposition reversal between the upper and the body.
 5. The methodset forth in claim 4, wherein the at least one peripheral protrusionextending beyond the peripheral edge defining a top abutment surface isdisplaced generally downward relative to the top face of the body.
 6. Ashoe comprising an outsole made of a natural or synthetic rubbermaterial, the outsole comprising a substantially flat body with a topface and a lower face, and having a selected distribution of treadprotrusions comprising at least one peripheral protrusion projectingfrom the peripheral edge of the body, the at least one peripheralprotrusion extending beyond the peripheral edge defining a top abutmentsurface displaced generally downward relative to a top face of the body.